Nanocomposites of nanocrystalline cellulose for biosensor applications

In this work, we describe the use of a composite material made of a renewable source and metallic nanoparticles for biosensing applications. NCC is a product isolated from natural cellulose fibers, which is of approx. 100 nm long and 10 nm wide in size. We augmented the surface area and chemical affinity of NCC by optimally dressing it with gold nanoparticles (AuNP). The deposition of AuNP on NCC was controlled by using cationic Polyethylenimine (PEI). AuNPs were thio-funtionalized prior to enzyme immobilization and the enzyme (glucose oxidase) was conjugated on the composite by carbodiimide (EDC)/NHS coupling. Using UV-visible and fluorescence spectroscopy in the presence of a specific substrate we monitored the activity of the immobilized enzymes, and its efficiency was compared with that of the enzyme in free form. Our results using FT-IR and SEM show that thiol-AuNPs were attached to the surface of NCC. The enzymes activity were measured and quantified using different kit assays and proved that the enzymes were attached to the support and maintained their activity.Peer reviewed: YesNRC publication: Ye